The GRID3 NGA - Settlement Extents v3.1 consists of a geographic representation of settlements in Nigeria, in two forms: 1) settlement polygons, and 2) spatial points depicting the centroids of settled grid cells at 3-arc seconds (or ~100 meters) contained within settlement polygons. Both layers include attributes as described in the codebooks. Data inputs and methodology is described in this document. The current version supersedes GRID3 NGA - Settlement Extents v3.0; the following changes were made: ● Corrections on imputed values for building count and building areas. ● Edits to the data release notes